/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.operators;

import org.apache.flink.api.common.ExecutionConfig;
import org.apache.flink.api.common.functions.FlatJoinFunction;
import org.apache.flink.runtime.operators.testutils.DriverTestBase;
import org.apache.flink.runtime.operators.testutils.UniformRecordGenerator;
import org.apache.flink.runtime.testutils.recordutils.RecordComparator;
import org.apache.flink.runtime.testutils.recordutils.RecordPairComparatorFactory;
import org.apache.flink.types.IntValue;
import org.apache.flink.types.Record;
import org.apache.flink.types.Value;
import org.apache.flink.util.Collector;

import org.junit.Assert;
import org.junit.Test;

public class JoinTaskExternalITCase
        extends DriverTestBase<FlatJoinFunction<Record, Record, Record>> {

    private static final long HASH_MEM = 4 * 1024 * 1024;

    private static final long SORT_MEM = 3 * 1024 * 1024;

    private static final long BNLJN_MEM = 10 * PAGE_SIZE;

    private final double bnljn_frac;

    private final double hash_frac;

    @SuppressWarnings("unchecked")
    private final RecordComparator comparator1 =
            new RecordComparator(
                    new int[] {0}, (Class<? extends Value>[]) new Class[] {IntValue.class});

    @SuppressWarnings("unchecked")
    private final RecordComparator comparator2 =
            new RecordComparator(
                    new int[] {0}, (Class<? extends Value>[]) new Class[] {IntValue.class});

    private final CountingOutputCollector output = new CountingOutputCollector();

    public JoinTaskExternalITCase(ExecutionConfig config) {
        super(config, HASH_MEM, 2, SORT_MEM);
        bnljn_frac = (double) BNLJN_MEM / this.getMemoryManager().getMemorySize();
        hash_frac = (double) HASH_MEM / this.getMemoryManager().getMemorySize();
    }

    @Test
    public void testExternalSort1MatchTask() {
        final int keyCnt1 = 16384 * 4;
        final int valCnt1 = 2;

        final int keyCnt2 = 8192;
        final int valCnt2 = 4 * 2;

        final int expCnt = valCnt1 * valCnt2 * Math.min(keyCnt1, keyCnt2);

        setOutput(this.output);
        addDriverComparator(this.comparator1);
        addDriverComparator(this.comparator2);
        getTaskConfig().setDriverPairComparator(RecordPairComparatorFactory.get());
        getTaskConfig().setDriverStrategy(DriverStrategy.INNER_MERGE);
        getTaskConfig().setRelativeMemoryDriver(bnljn_frac);
        setNumFileHandlesForSort(4);

        final JoinDriver<Record, Record, Record> testTask = new JoinDriver<>();

        try {
            addInputSorted(
                    new UniformRecordGenerator(keyCnt1, valCnt1, false),
                    this.comparator1.duplicate());
            addInputSorted(
                    new UniformRecordGenerator(keyCnt2, valCnt2, false),
                    this.comparator2.duplicate());
            testDriver(testTask, MockMatchStub.class);
        } catch (Exception e) {
            e.printStackTrace();
            Assert.fail("The test caused an exception.");
        }

        Assert.assertEquals("Wrong result set size.", expCnt, this.output.getNumberOfRecords());
    }

    @Test
    public void testExternalHash1MatchTask() {
        final int keyCnt1 = 32768;
        final int valCnt1 = 8;

        final int keyCnt2 = 65536;
        final int valCnt2 = 8;

        final int expCnt = valCnt1 * valCnt2 * Math.min(keyCnt1, keyCnt2);

        addInput(new UniformRecordGenerator(keyCnt1, valCnt1, false));
        addInput(new UniformRecordGenerator(keyCnt2, valCnt2, false));
        addDriverComparator(this.comparator1);
        addDriverComparator(this.comparator2);
        getTaskConfig().setDriverPairComparator(RecordPairComparatorFactory.get());
        setOutput(this.output);
        getTaskConfig().setDriverStrategy(DriverStrategy.HYBRIDHASH_BUILD_FIRST);
        getTaskConfig().setRelativeMemoryDriver(hash_frac);

        JoinDriver<Record, Record, Record> testTask = new JoinDriver<>();

        try {
            testDriver(testTask, MockMatchStub.class);
        } catch (Exception e) {
            e.printStackTrace();
            Assert.fail("Test caused an exception.");
        }

        Assert.assertEquals("Wrong result set size.", expCnt, this.output.getNumberOfRecords());
    }

    @Test
    public void testExternalHash2MatchTask() {
        final int keyCnt1 = 32768;
        final int valCnt1 = 8;

        final int keyCnt2 = 65536;
        final int valCnt2 = 8;

        final int expCnt = valCnt1 * valCnt2 * Math.min(keyCnt1, keyCnt2);

        addInput(new UniformRecordGenerator(keyCnt1, valCnt1, false));
        addInput(new UniformRecordGenerator(keyCnt2, valCnt2, false));
        addDriverComparator(this.comparator1);
        addDriverComparator(this.comparator2);
        getTaskConfig().setDriverPairComparator(RecordPairComparatorFactory.get());
        setOutput(this.output);
        getTaskConfig().setDriverStrategy(DriverStrategy.HYBRIDHASH_BUILD_SECOND);
        getTaskConfig().setRelativeMemoryDriver(hash_frac);

        JoinDriver<Record, Record, Record> testTask = new JoinDriver<>();

        try {
            testDriver(testTask, MockMatchStub.class);
        } catch (Exception e) {
            e.printStackTrace();
            Assert.fail("Test caused an exception.");
        }

        Assert.assertEquals("Wrong result set size.", expCnt, this.output.getNumberOfRecords());
    }

    public static final class MockMatchStub implements FlatJoinFunction<Record, Record, Record> {
        private static final long serialVersionUID = 1L;

        @Override
        public void join(Record value1, Record value2, Collector<Record> out) throws Exception {
            out.collect(value1);
        }
    }
}
